Refrigerator compressor



v; March 9, 1943.- I BENZ 1 REFRIGERATOR COMPRESSOR Filed April 5, 19406 Sheets-Sheet 1 M r h 9,1943. LAMBEN Z- 2,313,214 REFRIGERATOR CQMPRESSOR 7 Filed A ril 5, 1940 e Sheets-Sheet 2 j'y. Z.

March 9, 1943. 1. .w. BENZ 2,313,214 REFRIGERATOR coMPREssoR Filed April5, 1940 I 6 Sheets-Shed s March 9, 1943. L. w. BENZ v REFRIGERATORCOMPRESSOR Filed Apri1'5, 1940 6 Sheets-Sheet 4//////////////W/////////fl//W/i March 9, 1943.

L. W. BENZ I REFRIGERATOR COMPRESSOR Filed April 5, 1940 6 Sheets-Sheet5 42' .54 I 50 62 so 46 March 9,' 1943.

L. W. BENZ REFRIGERATOR coMPREs'sori s Sheet s-Sheet 6 Filed April 5,.1940

Flg. 3,

Patented Mar. 9, 1943 REFRIGERATOR CONER-ESSOR Leonhardt W. Benz,Mobile, Ala. Application April 5, 1940, Serial No. 328,117

9 Claims.

uneconomical in operation, particularly for refrigerating apparatus usedin connection with air conditioning systems.

The presently to be disclosed compressor or pump possesses inherentqualities which result in great displacement of fluid in proportion tothe physical dimensions of the unit, and the illustrative design is suchthat one revolution of the driving shaft will cause two completecompression stages, each equal to approximately three-quarters of theentire displacement of the annular piston cylinder.

A further advantage of this compressor is its ease of manufacture andfabrication, and the comparatively small input of power required todrive the machine in relation to the comparatively large volume of gascompressed and con sequently liquefied.

Briefly, the present invention comprises a completely housed compressorunit having identical and interchangeable right and left-hand geartrains and annular cylinder blocks in association with continuouslymoving pistons.

Other novel features of improvement contributing to ease and'efiiciencyin operation will be perceived'and readily understood from. reading thefollowing detailed description of a preferred embodiment of theinvention in connection with the accompanying drawings, in which Fig. 1is a side elevation of the compressor, partly in section, and showingthe power-operating means;

Fig. 2 is a vertical section taken on line 2-2 of Fig. 1, looking in thedirection of the arrows;

Fig. 3 is a vertical section taken on line 3-3 of Fig. 1, looking in thedirection of the arrows;

Fig. 4 is a longitudinal vertical section;

Fig. 5 is a sectional plan View taken on line 55 of Figs. 2 and 3;

Fig. 6 is a vertical section of a piston and part of a cylinder membertaken on line 0-43 of Fig. 7 is a cross sectional view of a cylindermounted piston taken on line 'l-l of Fig. 6;

Figs. 8, 9 and 10 are schematic showing of the right-hand gear trains at0 or 360, and 240 positions of rotation, respectively;

Figs. 11, 12 and 13 are similar schematic showings of the left-hand geartrain at 0 or 360, 120 and 240 positions of rotation, respectively; and

Figs. 14, 15 and 16 are diagrammatic views of the positions of thepistons and valves corresponding with the 0 or 360, 120 and 240positions respectively of the gear trains. Referring more specificallyto the drawings, numeral l denotes a rectangular casing or housing inwhich all of the compressor or pump opcrating mechanism is sealed. Oneside of the housing I is provided with a removable cover plate 2,whereby complete access may be had to the interior of the casing. Ahorizontal drive shaft 5 is mounted in the upper portion of the casingand supported in bearings 6 contained in inwardly projecting tubularextensions 1 formed integrally in opposite end walls of the housing l.One end of the shaft 5 extends out wardly beyond the housing l through aconventional, flexible, shaft seal 8 retained in a tubular extension 9having a sealed apertured end plate Ill. The apertured bearing 6supporting the opposite end of the drive shaft 5 is covered and sealedby a plate I I that is suitably bolted to the housing. The drive shaft 5may be rotated through the medium of pulley l2, flexible belts l3, andmotor IA, preferably positioned horizontally and attached directly onthe top of the unit housing I. ible driving means may be founddesirable, or, if preferred, direct drive means may be employed.

A fixed horizontal shaft 20 in the lower portion of the casing ismounted in opposed, in-

turned flanges 2! which are integral with the I Referring now to Figs. 1and 4, it will be seen that the operating or fluid displacementmechanism of the unit consists of right and left-hand In some instances,other flexgear trains, circular cylinder sections or members, andpistons, the sets of gear trains being denoted broadly as 36 and 3!,respectively.

The right and left-hand cylinder sections and pistons are identical andthe parts of each group are interchangeable so that the correspondinggear or other component may be used for either the right or left-handtrain; and consequently, the number of different parts to bemanufactured as well as the spare parts which must be stocked is kept ata minimum.

A clear understanding of the apparatus will ensue from a description ofone of the sections, and in this connection, the right-hand half of theunit denoted by numeral 36 now will be taken up in detail. An upperstepped gear 35 having a large diameter 36 and a small diameter 31 issecured through integral ofiset hub portion 35 1 and stud bolt 39* tothe drive shaft 5. The outer face of the gear '35 abuts the inner end ofthe inturned, tubular bearing support 1, so that when the right andleft-hand gears are secured to the shaft, they completely fill the spacebetween the side bearing holders or supports 1.

As shown in Fig. 2, the upper, double diameter gear 35 is provided witha partial series of teeth on both peripheries 35 and 31. The partialseries of gear teeth do not lie in the same circular sectors, butterminate approximately on the same radial lines from the axis of theircenters.

The segmental series of teeth on the diameters 36 and 31 mesh withcorresponding segmental series of teeth 38 and 39, respectively, cut onthe different diameter steps formed on the periphery of the right-handhalf of cylindrical cylinder block 40. That is to say, the stepped gearmeans on the block may be joined therewith in an integral manner.

The right-hand half of the cylinder block 46 is mounted on fixed shaft20 with the smaller diameter step 38 of the block abutting a thrustbearing 4| positioned between the block and the inner edge of inturnedflange 2 I.

In Fig. 2 of the drawings, a vertical section is shown of the right-handdriving means or train of gears which illustrates the meshing of theteeth of the upper larger diameter gear 36 with the teeth of the lowersmaller diameter gear 38, together with the concomitant meshing of theupper smaller diameter gear (31) teeth with the larger diameter lowergear (39) teeth. The

partial series of teeth on the several gears mesh in the manner shown inFig. 2 when the compressor or pump is at the 0 or 360 position of itsrotation, (see also Fig. 8). left-hand train of gears is in an oppositeposition as diagrammatically shown in Fig. 11 of the drawings.

Each half of the cylinder block 40 is formed with a continuous, annulargroove 4 I in its inner abutting face so that the complete cylinderchamber is made up of the two identical halves and is circular in bothoutline and cross-section. An annular groove or slot is provided in eachhalf of the cylinder block 40 outwardly of the cylinder chamber, and aflexible spring ring or strip 46 is inserted therein to act as a fluidseal and prevent leakage between the relatively rotatin'g abutting facesof the cylinder halves.

Each half of the cylinder block 40 is also provided with a laterallyextending, relatively short, substantially circular piston 50 which isdoublefaced. These pistons 56 each have a circular shoulder or flange 5|around a minor portion of theirrespective peripheries for engagementwith At this time, the

a complemental groove 52 milled below a semicircular socket 53 in whichhalf of the piston:

fits. The pistons 50 are retained in fixed position through the mediumof a countersunk belt or screw 54 arranged to insure that theinnerportion of the piston will be drawn tightly against the innerperipheral wall of the socket 53. Preferably piston rings 55 are placedaround the peripheral edge of the piston to provide a gas-tight fit withthe opposite half of the cylinder chamber.

Each half of the cylinder block is fitted with a spring-pressed inletvalve 60, preferably located within the cylinder chamber for the intakeof gas, such as a refrigerant vapor, through respective passages 6|communicating with the interior of the casing or housing I, as shown inFig. 4. These inletvalves may be of any form, as, for instance, the typeshown, which comprises a screw nipple 6! having an arbor 62 on the outeror cylinder chamber end thereof carrying a spring-pressed, one-way checkvalve 63.

The compressed gas is discharged from the cylinder chamber througheither one of the two respective ports 65, which are formed in each halfof cylinder block 40, as said ports pass in rotation by passage 26communicating with bore 25 in fixed shaft 20.

The series of drawings, Figs. 8 to 16, inclusive, show the simultaneouspositions of both right and left gear trains and the relative positionsof their respectively associated pistons (50) and inlet and outlet means(66 and 65) when in 0, 240 and 360 positions of rotation. Fig. 8illustrates the meshing of the upper and lower members of the right-handgear train at 0 or 360, while Fig. 11 is a similar view of the lefthandtrain of gears at this time. Fig. 14 shows the position of the pistons(50) and valves (66) attached to the two halves of the cylinder block 40at 0 or 360, with the left-hand piston and valve in solid lines and theright-hand piston and valve in dotted lines. At this stage, compressedgas may be discharged through discharge means or port 65 of the dottedright-hand cylinder half, the one-way inlet valve 60 for this half beingheld closed by the superior pressure within the communicating portion ofthe cylinder. The other inlet valve 60 (which is shown in full lines)can now supply gas at casing (I) pressure to the low-pressure cylinderspace between the other faces of the pistons. A comparison of therighthand gear train of Fig. 8 with the corresponding position of theleft-hand gear train of Fig. 11 shows that the former is aligned so asto commence driving its piston at greater angular speed than the driveshaft 5, and the latter to commence driving its piston at a lesserangular speed.

Therefore, when the shaft 5 has turned the large gear 36 clockwise 120to the position of Fig. 9, the 240 rotation of meshed small gear 38 inan opposite direction will have caused the righthand piston connecteddirectly therewith to progress the same angular distance to the dottedline position of Fig. 15. However, the full line left-hand pistonindicated in Fig. 15 will. have advanced only 60 by virtue of the factthat it has been driven at its slower speed by the inverse gear ratioshown moving into mesh in Fig. 11. The difierential approach movement ofthe two pistons, therefore, compresses the included gas to approximatelyone-third of its initial volume.

Next considering the relative gear positions of Figs. 9 and 12, it willbe observed that the smalldrive shaft gear 31 is just cominginto meshwith the large cylinder gear 39, to drive the right-hand piston atreduced or slow speed, and that the lefthand piston gears (Fig. 12) havecompleted only half of their slow speed drive movement. From thisitfollows that there will be no relative motion between the pistons 50' asthey move counterclockwise from the Fig. 15 to-the Fig. 16, position.But such'slow motion has carriedthe compressed gas charge and the port65 to the left-hand cylinder member 4| past the radial discharge passage26 of the stationary shaft 20 to discharge said gas.

In completing the cycle of operation the, respective gear trains ofFigs. 10 and 13return to the or 360 condition of Figs. 8 and 11. That isto say, the final rotation of shaft through 120 continues the slow speeddrive of the righthand piston for aremaining 60 and drives the left-handpiston at its fast speed for 240 of angular movement, thus restoring thepistons and valves to the initial positions of Fig. 14. This final phaseof the cycle compresses a second gas charge and discharges the same whenthe righthand cylinder half port 65 returns to the aligned relation withdischarge passage 26, which Fig. 14 illustrates.

To summarize briefly: A cycle consists of a three-to-one compression ofa first charge accompanied by the intake of a second charge, a dischargeperiod for the first charge in which the second charge remainsuncompressed, and a three-to-one compression and discharge of the secondcharge. Movement of the two pistons 53 is continuous, and always in theopposite direction from that of the driving shaft 5. In this manner anannular cylinder is provided which is completely swept by the twopistons, and two compressions are obtained with a single rotation of thedriving element.

The compressed gas passes through a one-way' discharge valve at theouter end of shaft conduit or passage and into a suitable outlet valveH. From the valve H said gas is piped to any desired point of use, whilethe expanded gas or other relatively low-pressure fluid returns to thecompressor unit through casing opening 13 and by way of inlet valvecoupling 74.

While the invention has been described with particular reference to acertain cycle of compression and arrangement of driving gears, it willbe understood that within the scope thereof other arrangements arepossible which will result in a synchronous and continuous rotation ofthe relatively movable pistons and cylinder members with inversion ofthe speed ratios during the cycle. Accordingly, it is not intended thatthis invention be limited to the details of construction which arespecifically illustrated, except as may be required by the appendedclaims.

Having thus described my invention, what I claim as novel and desire tosecure by Letters Patent of the United States is:

1. In a rotary pump, a pair of identical relatively movable cylindermembers formed and arranged completely to provide an annular cylinderchamber; a piston fixed to each movable member and operatively disposedwithin said cylinder chamber; means for synchronously rotating thecylinder members in the sam direction at difierent angular speeds duringone part of a revolution, at an inverse ratio of speeds still in thesame direction during another part of the revolution, and at the samespeed in the same direction for the balance of the revolution; and inletand outlet means arranged to admit fiuid to the cylinder chamber and toexhaust fluid inwardly therefrom in a radial direction after it hasbeenacted upon by the pistons.

2., In a rotary pump, a fixed shaft having a closed conduit formedtherein and extending from an opening intermediate its ends through oneend; a pair of relatively rotatable cylinder members formed and arrangedto provide halves of'a cylinder block having an annular cylinder chamberand rotatably mounted on the shaft; a cylindrical'piston fixedlyconnected to each cylinder member and operatively disposed within saidcylinder chamber; gear means for synchronously rotating the cylindermembers always in the same direction and at different angular speedsduring one part of a revolution, at an inverse ratio of speeds duringanother part of the revolution, and at the same speed for the balance ofthe revolution; and inlet means arranged to admit fluid to the cylinderchamber, said cylinder members each having a passage extending inwardlyfrom the annular cylinder chamber and adapted to communicate with theconduit of the fixed shaft to exhaust fluid after it has been acted uponby the pistons.

3. A refrigerator compressor unit comprising, in combination, a pair ofidentical cylinder members formed and arranged completely to provide anannular cylinder chamber which is divided between said cylinder memberstransversely with respect-to the axis of said cylinder chamber; a pistoncarried rigidly by each cylinder member'and' operatively disposed withinthe cylinder chamber; gear means for rotating the cylinder members andpistons synchronously and relatively in the same direction; a sealedcasingenclosing the cylinder members and gear means to provide anaccumulator for low presentrance of vapor from the casing; and a conduitpassage leading from the cylinder chamber to without the sealed casing.

4. A refrigerator compressor unit comprising, in combination, a fixedshaft having a conduit therein extending from a point intermediate itsouter surface length to one end thereof; a pair of cylinder membersmounted freely on said shaft formed and arranged to provide halves of acylinder block having an annular cylinder chamber which is dividedbetween said cylinder members transversely with respect to the axis ofsaid cylinder chamber; a piston carried by each cylinder member andoperatively disposed within the cylinder chamber; gear means forrotating the cylinder members and pistons synchronously and relativelyin the same direction; a sealed casing enclosing the cylinder membersand gear means to provide an accumulator for low pressure refrigerantvapors; a oneway check valve in each cylinder member arranged to permitentrance of vapor from the casing; and a conduit passage leading fromthe rotating cylinder chamber to the conduit of the fixed shaft andthence without the sealed casing.

5. In a rotary pump, an identical pair of relatively movable, circularcylinder members, each cylinder member having a circular groove ofsemi-circular cross-section oppositely disposed with respect to that ofthe other cylinder member to provide an annular cylinder chamber; acylindrical piston detachably secured across the groove of each cylinderso that one half of its effective area will extend into. the oppositegroove; a fixed shaft on which the cylinder members are supported forfree rotation; a stepped gear integrally formed on the outer: endsurface of each cylinder member; a countershaft rotatablysupported inspaced parallel relation to said fixed shaft;; a. pair of identicalstepped gears secured. to said countershaft for rotation therewith andarranged to drive the respective cylinderv gears, each of the gearshaving only a partial toothed'segment on each of its steps, andthetoothed segments being of a size and angular arrangement to driveeach cylinder. member at greater. and lesser speeds than thecountershaft and to produce relative movement of the pistons; means foradmitting fluid to the cylinder chamber; and means for exhausting fluidfrom the cylinder chamber.

6. In:a rotary pump, a pair of relatively movable, circular cylindermembers, each cylinder member having a circular groove of semi-circularcross-section oppositely disposed with respect to that of theothercylinder member to provide.

an annular cylinder chamber; a relatively short, double-faced,cylindrical piston detachably secured across the groove of each cylinderso that one half of its effective area will extend into the oppositegroove; afixed shaft on which the cylinder membersv are. supported forfree rotation; a stepped gear formed on the outer end surface of eachcylinder member; a countershaft rotatablysupported in spaced parallelrelation to said fixed shaft; a pair of identical stepped gears securedto said countershaft for rotation therewith and arranged to drive therespective cylinder gears, each of the gears having only a' partialtoothed segment on each of its steps, and the toothed segments being ofa size and angular arrangement, to drive each cylinder member at greaterand lesser speeds than the countershaft and to produce relative movementof the pistons; means for admitting fluid to the cylinder chamber; andmeans for exhausting fluid from the cylinder chamber.

'7. In a rotary pump, a pair of relatively movable, circular cylindermembers, each cylinder member having a circular groove of semi-circularcross-section oppositely disposed with re spect to that of the othercylinder memberv to provide an annular cylinder chamberya cylindricalpiston detachably secured across the groove of each cylinder so that onehalf of its eiiective area will extend into the opposite groove; a fixedshaft on which the cylinder members are supported for free rotation; astepped gear formed onthe outer surface of each cylinder -member; acountershaft rotatably supported in spaced parallel relation to saidfixed shaft; a pair of identical stepped gears secured to saidcountershaft for rotation therewith and arranged to drive the respectivecylinder gears, each of the gears having only a partial toothed segmenton each of its steps, and the toothed segments being of a size andangular arrangement to drive each cylinder member at greater and lesserspeeds than the countershaft and toproduce relative movement of thepistons; a'

sealed casing enclosing the cylinder members and stepped gears; andmeans for admitting fluid irom the casing to the cylinder chamber, saidfixed shaft and cylinder members being provided with means forexhausting fluid from" the chamber and exteriorly of said casing.

8. In a rotary refrigerator compressor, a pair of relatively movable,circular cylinder members, each cylinder member having a circular grooveof semi-circular cross-section oppositely disposed with respect to thatof the other cylinder memher to provide an annular cylinder chamber; acylindrical piston detachably secured across the groove of each cylinderso that one half of its efiective area Will extend into the oppositegroove; a fixed shaft on which the cylinder members are supported forfree rotation; a stepped gear integrally formed on the outer surface ofeach cylinder member; a countershaft rotatably supported in spacedparallel relation to said fixed shaft; a pair of identical stepped gearssecured to said ccuntershaft for rotation therewith and arranged todrive the respective cylinder gears, each of the gears having only apartial toothed segment on each of its steps, and the toothed segmentsbeing of a siZe and angular arrangement to drive each cylinder member atgreater and lesser speeds than the countershaft and to produce relativemovement of the pistons; a sealed housing enclosing the cylinder membersand gears; driving means for the gears carried by the housing, saidcountershaft having an end projecting outside the housing and connectedwith the driving means; means for admitting fluid to the cylinderchamber; and

means for exhausting fluid from the cylinder" chamber.

9. As a sub-combination, a circular cylinder member having an annulargroove of semi-circular cross-section coaxially arranged on an end facethereof, and a relatively small groove extending transversely of theannular groove; a'

cylindrical piston of substantially the same diameter as the annulargroove and provided with a peripheral flange complemental to said smallgroove, the said flange and small groove being interengaged to preventrotation of the piston; a piston ring encircling the piston; and screwmeans for detachably securing the piston and its ring in the positionsrecited.

LEONHARDT W. BENZ.

